Peristaltic pump with means to vary relative pumping volume between tubes

Abstract

A device for entering dyes having a consistency, which may vary from a liquid to a pulverous state, into synthetic material processing machines, especially extrusion and injection molding machines, by means of a hose pump adjustable as to the quantity being delivered thereby. The device includes a rotor provided with rollers respectively rotatable about their own axes and about the axis of the rotor in the manner of planetary gears while at least one compressible conveyor hose of elastic material extends in contact with the rollers and between the latter and the interior of a pump housing which interior has a substantially circular cross section. The rollers roll on the hose or hoses while compressing same sectionwise and while the pressure zones circulate about the axis of the rotor. For purposes of adjusting the delivery quantity of the pump per revolution of the rotor, and adjusting device is provided for varying the hose volume respectively remaining between the pressure zones.

What we claim is: 
     
       1. A device for entering dyes of from liquid to pulverous consistency into synthetic material processing machines, especially extrusion and injection molding machines, which includes a hose pump comprising a housing having an inner peripheral circular section, a rotor rotably arranged within said housing section and having an outer marginal portion, motor means drivingly connected to said rotor for rotating the same, a plurality of rollers rotatably connected to said outer marginal portion of said rotor and being distributed around said rotor in spaced relationship to each other, at least one compressible conveyor hose means of elastic material contacted by said rollers and extending between said rollers and said inner peripheral housing section at least half about said rotor so that in response to the rotation of said rotor said rollers roll on said hose means while compressing successive sections thereof, and means for varying the volume of said hose means between the respective hose means sections being compressed to thereby adjust the delivery quantity of said pump per revolution of said rotor, said compressible conveyor hose means including at least two hoses, said means for varying the volume of said hose means between the respective hose means sections being compressed includes an adjusting device for displacing at least one conveyor hose means in axial direction of said pump housing, said adjusting device extending from the outside of said pump housing into the interior thereof. 
     
     
       2. A device according to claim 1, in which said compressible hose means comprise a plurality of exchangeable hoses. 
     
     
       3. A device according to claim 2, in which said exchangeable hoses have substantially the same outer diameter. 
     
     
       4. A device according to claim 1, in which said housing has an inner conical circumferential surface. 
     
     
       5. A device for entering dyes of from liquid to pulverous consistency into synthetic material processing machines, especially extrusion and injection molding machines, which includes a hose pump comprising: a housing having an inner peripheral circular section, a rotor rotatably arranged within said housing section and having an outer marginal portion, motor means drivingly connected to said rotor for rotating the same, a plurality of rollers rotatably connected to said outer marginal portion of said rotor and being distributed around said rotor in spaced relationship to each other, at least one compressible conveyor hose means of elastic material contacted by said rollers and extending between said rollers and said inner peripheral housing section at least half about said rotor so that in response to the rotation of said rotor said rollers roll on said hose means while compressing successive sections thereof, and means for varying the volume of said hose means between the respective hose means sections being compressed to thereby adjust the delivery quantity of said pump per revolution of said rotor, said housing having an inner conical circumferential surface, said means for varying the volume of said hose means between the respective hose means sections being compressed includes an adjusting device for displacing at least one conveyor hose means in axial direction of said pump housing, said adjusting device extending from the outside of said pump housing into the interior thereof. 
     
     
       6. A device according to claim 5, in which the axes of rotation of said rollers are at least approximately parallel to a mantle line of said inner circumferential surface of said housing. 
     
     
       7. A device according to claim 5, in which the axes of rotation of said rollers extend substantially parallel to the axis of rotation of said rotor. 
     
     
       8. A device according to claim 5, in which said pump housing has a slot through which said adjusting device extends into the interior of said pump housing, said slot extending along a mantle line of said pump housing. 
     
     
       9. A device according to claim 5, in which said motor means is a constant speed motor. 
     
     
       10. A device according to claim 5, which includes an infinitely variable transmission between said motor and said pump.